export type CanvasNodeStackOrder = string[];

/**
 * Keeps the most recently interacted node at the end of the paint order.
 * This is session-local UI state and is intentionally not persisted with the
 * canvas document.
 */
export function bringCanvasNodeToFront(order: CanvasNodeStackOrder, nodeId: string): CanvasNodeStackOrder {
    if (!nodeId) return order;
    if (order.at(-1) === nodeId) return order;
    return [...order.filter((id) => id !== nodeId), nodeId];
}

/**
 * Applies the interaction order while preserving the relative order of nodes
 * that have not been interacted with yet.
 */
export function sortCanvasNodesByStackOrder<T extends { id: string }>(nodes: T[], order: CanvasNodeStackOrder): T[] {
    if (nodes.length < 2 || order.length === 0) return nodes;
    const rankById = new Map(order.map((id, index) => [id, index]));
    return nodes
        .map((node, index) => ({ node, index, rank: rankById.get(node.id) ?? -1 }))
        .sort((left, right) => left.rank - right.rank || left.index - right.index)
        .map(({ node }) => node);
}